Inspection before production of sheet metal parts, inspection methods for materials, and issues to be noted during processing

Pre production inspection of sheet metal parts and material inspection methods:

1. Oil inspection

Use clean gauze to wipe the outer surface of the covering parts clean. Apply oil evenly along the same direction with a clean brush to the entire outer surface of the stamped part. Place the oiled stamped parts under strong light for inspection, and advocate to place the stamped parts vertically in the direction of the vehicle body. By using this method, it is easy to detect small pits, indentations, and ripples on stamped parts

2. Visual Inspection

Visual inspection is mainly used to discover the appearance abnormalities and microscopic defects of stamped parts.

3. Contact Inspection

Use a clean gauze to wipe the surface of the outer cover clean.

. The inspector needs to wear contact gloves and closely adhere to the surface of the stamped part along the longitudinal direction. This inspection method depends on the inspector's experience. When necessary, suspicious areas that have been detected can be polished with an oilstone and verified, but this method is still an effective inspection method

4. Flexible mesh polishing

Use a clean gauze to wipe the outer surface of the outer cover clean.

. Use a flexible sanding net to closely adhere to the surface of the stamped part and polish it longitudinally to the entire surface. Any pitting or indentation will be easily detected

5. Oil Stone Polishing

①. First, clean the surface of the outer covering with a clean gauze, and then use an oil stone for polishing. For areas with arcs and difficult to reach areas, use relatively small oil stones for polishing.

② The selection of oil stone particle size depends on the surface condition.

. Advocate using fine-grained oilstones. The direction of oilstone polishing is basically carried out along the longitudinal direction, and it fits well with the surface of the stamped part. In some areas, it can also compensate for horizontal polishing

Issues to pay attention to during sheet metal processing:

1. Scratches on stamped parts: The reason for scratches on the parts is that there are sharp scratches or metal dust falling into the mold. Avoidance measures include grinding the scratches and metal dust on the mold.

2. Cracking at the bottom of the part: The reason for cracking at the bottom of the part is due to poor plasticity of the data or excessive pressure on the mold edge pressing ring. Avoidance measures include replacing the data with better plasticity or loosening the edge pressing ring

3. Wrinkles on the side walls of parts: The reason for wrinkles on the side walls of parts is that the thickness of the data is not enough (thinner than the agreed thickness) or there is eccentricity during the upper and lower mold devices, resulting in a large gap on one side and a small gap on the other side. The preventive measures are to replace the data immediately and readjust the mold